Train stop mechanism



1949 G. G. ENSIGN ET AL 2,483,057

TRAIN STOP MECHANISM Filed June 18, 1945 i l6 MHH I L H111I1II1111111111I11I7 R15 29 U A .IIII

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Patented Nov. 15, 1949 George G. Ensign,

'Schaefer, and Wenze National- Watch "Company,

assignors "120 "Elgin Robert R. Lawson, Earl H.

l M. W ochos, 'J r., Elgin, 111.,

Elgin, 111.,- a eorporation'of Illinois Application June 18, 1945, Serial No. 600,040

2 Claims.

It "is often"de'sirable' to provide stop mechanisms to prevent motion of clockwork devices. For example, a spring driven chronometer may be provided with aremovable escapement assembly; and means are desired to prevent rundown of the spring; with possible damage due to the abnormal motionywhen the escapement assembly is removed. 7 I

A"'fea'ture of this'inventio'n is the provision of a stop mechanism with means for moving a stop latch into and out-of blockingposition with relation to the clock train.

Another feature of this invention is the provisio'n'of a stop" mechanism having a springactuated 'de'tent which tends normally "to block the train,but"whichis -moved during the operation of asseniblyof the parts sothat the train is released for its proper motion.

, Another feature is the provision of an assembly including aclockwork having aremovable escapement which is secured in position by a screw, a stop mechanism ha ing a spring-actuated detent which tends normally to block the train, and in which the operation of en aging the screw moves the stop mechanism to ineffective position.

An illustrative form of practice of the invention is shown on the accompanying drawing, in which:

Figure 1 is a side elevation of a chronometer, with part of a illar broken away to show stop mechanism elements.

Figure 2 is a sectional view, on an axial section throu h the illar, with the stop latch in disen a ed position, substantially on line 2-2 of Fi ure 1.

Fi ure 3 is a view corresponding to Figure 2, but with the sto latch in en aged osition.

The stop mechanism is illustrated as employed with a chronometer which has the pillar plate I 0, the train plate II, and the connecting and spacing pillars I2, I3 held by the screws I4. The usual parts inclusive of main spring, gear train, hands, and the like are provided, but for clarity of the drawing this train is shown only as the fourth wheel l5. Such structures are well-known, and no invention is claimed therein.

A removable escapement assembly is shown, which may be of the form shown and claimed in the copending application Serial No. 633,946, filed December 10, 1945, to which reference is made for details of assembly and construction. For purposes of the instant invention, it is sufficient that this assembly has a balance cock I8 which is secured to the train plate by using balance cock 2 mounting screws I9 of which one is shown as threaded into the underlying pillar I3. When suchscrews IS are removed, the balance cock I8 may be'lifted awayjcarrying with it the escape- "ment and thereby releasing'the train from the normal timing controls. It is customary to provide locating dowels 20,0r closely fitted surfaces at the edges of thebala'nce cock,whereby to assure accuracy of positioning.

According tothe illustrated form, the pillar I3 has an axialslot' 25 through which extends an arm '25 of the train stop latch, this arm having an upturned outer'end 21 for engaging in an aperture 28, of which one'or more are provided in the 'fourth wheel I5. Within the pillar I3, the

latchhas aknee'29 'and a shank'portion 30, the latter extending upwardly into the path of axial seating movement of the balance cock mounting screw"l9.

A'coil spring 33 is provided'withinthe pillar I3, and engagesbetweenthebottom of theknee 29 and the inner end of the securing screw I4 (Figures 2 and 3). By removing the screw M, the spring 33 can be withdrawn.

In operation, when all parts are assembled, the stop mechanism is in the position of Figure 2, with the end 21 free of the fourth wheel I5. The chronometer runs and keeps time. If, for any reason, it is desired to remove the escapement assembly, the balance cock mounting screw I9 is turned, so that it rises in the pillar I3. Under the urge of the spring 33, the latch follows the screw I9, until its end 21 engages the fourth wheel or enters an aperture 28 thereof. The latch is loosely fitted in the pillar I3, so that it can rock in its own plane, i. e. in a radial plane through the axis of the pillar. When the screw I 9 has been raised a distance sufiicient to permit the balance cock I8 to be moved for rotation about the axis of this screw, as for example by separation of the dowel 20 from its reception cavity, the latch has attained a position for stop engagement. If the fourth wheel It has not presented an aperture 28 for the end 21, a partial rotation of the fourth wheel effects this presentation: and thus the latch attains the position of Figure 3, in which it blocks the fourth wheel and stops the train. The screw I9 can then be completely removed, without further event, and the balance cock I8 separated from the train plate without releasing the train to run down.

When the parts are to be assembled again, the balance cock I8 is placed accurately in position and the escapement therewith is meshed with the train; the screw i9 is seated and rotated. During the downward axial movement of the screw l9, it encounters the end of the shank portion 30, and depresses the latch, until ultimately the parts are in the position of Figure 2, with the fourth wheel I5 free to turn.

Thus, in the illustrated preferred form, the train is under control at all times, being either held to timed motion by the escapement, or held in stopped position by the latch: and no special manual operation or care need be observed to accomplish these results.

It will be noted that the pillar 13 can perform its normal function of spacing the plates H], .II

and that the screws I 4, well as the balance cock l8, againstseparation when the parts have been assembled.

It is obvious that the invention is not limited to the specific illustrated form, but may be em ployed in many ways within the scope of the appended claims.

We claim: 7

1. A stop mechanism for a clockwork having plates separated by a pillar, a clock train having 7 an apertured fourth wheel, a demountable balance cock, and means connectable with the clock train to control the same, which comprises a latch axially movable in and guided by the pillar V for movement in a plane parallel to the axis of said wheel, and said latch having an outwardly projecting arm having an upturned end engageable in an aperture of the fourth wheel of the train, a spring in the pillar effective for urging the latch into blocking engagement with said fourth wheel, and a balance cock mounting screw for securing the balance cock in position, said screw being threadable into the pillar and effective at its lower end as the screw approaches final securing position to engage and move said latch axially along the pillar and out of blocking engagement with the fourth wheel.

I9 assurethese plates, as

said wheel.

2. A stop mechanism for a clock-work having plates separated by a pillar, a clock train mounted on said plates and having an apertured wheel, a demountable balance cock, and a screw for securing the balance cock in position; which comprises a latch having a portion guided in said pillar, said pillar being hollow and threaded internally at its end adjacent the position of the balance cock for receiving said screw, said pillar also having an axial slot leading from its central hollow to the exterior, said latch having a portion extending through said axial slot and guided thereby for axial movement along the slot and having-an outer end portion which in one position engages in an aperture of said wheel toblock the same against rotation, and a spring in the pillar and cooperative with the latch for urging the same into such blocking engagement,

said securing screw being efiective while being threaded into the pillar for moving said latch axially to disengage its said end portion from GEORGE G. ENSIGN. ROBERT R. LAWSON. EARL H. SCHAEFER. WENZEL M. WOCI-IOS, JR...

' REFERENCES CITED The following references are of record'in the file of this patent:

' UNITED STATES PA'I'ENTS Number Name 7 Date 230,262 Fitt July 20, 1830 v 1,378,408 Freund May 17, 1921 2,393,671 .Wo1fe Jan. 29, 1946 FOREIGN PATENTS Number V Country Date 85,421 Switzerland Oct. 1, 1920 100,993 Switzerland Sept. 1, 1923 

